When the Dark Knight released in 2008, it broke records and went on to cross a billion dollars at the worldwide box office, as well as going to #3 on the domestic box office list and staying there (until the Avengers crossed it this year). When the Dark Knight Rises was about to release this year, it was to overwhelming expectations and fanfare - many thought it would break its predecessor's records and set a new record for opening weekend, opening day, etc. 
Alas, we all know what happened that weekend - while it certainly almost set a couple of records with many people opting to go to the movie anyway, the Aurora shooting had a major negative impact on the box office. The press promotion for Dark Knight Rises was cut short, and all the stars returned home to a somber country.
Warner Brothers, out of repesct for the victims and those affected by the tragedy, cut all their promotion and advertising for that week, and a lot of people decided not to go to the theatres, opting to wait for later or wait for the DVD.
Despite the dark cloud surrounding the industry for those few weeks, it's rebounded somewhat, and the Dark Knight Rises is continuing to go strong, althought not as strong as Dark Knight. It's domestic grosses are $433 million, but its international grosses have exceeded that of the Dark Knight. This is to be expected, as blockbuster sequels generally tend to build overseas with each consecutive entry. Other examples of this phenomenon include all the Spiderman movies, the Lord of the Rings movies, and the Harry Potter movies.
As of this weekend, Box Office Mojo is reporting that the Dark Knight Rises is at 1,007 billion, whereas Dark Knight ended its run at 1,003 billion.
